Pseudo-mode-controlled Cosine Pseudo-Shell Correlation Beam And Mode-shift Imaging Studies

Random fluctuations are the basic characteristics of light fields,and the basic theory describing the statistics of light field fluctuations is optical coherence theory.Since it was proposed in the 1950 s,optical coherence has developed into one of the most important basic theories of modern optics(including classical and quantum).As an important intrinsic parameter of the light field,coherence has both time and space attributes,which affect the monochromaticity and directionality of the light field respectively.High spatial coherence laser has been widely used in many fields and has become the most basic cognition of laser.However,high spatial coherence can also bring harmful effects,such as coherence artifacts and imaging crosstalk,which seriously affect the application of lasers in imaging and display,material processing,lithography,holography,optical manipulation,and inertial confinement nuclear fusion.The optimization and control of laser coherence has become a subject that more and more optical science and technology development must face.This dissertation innovatively studies the design theory and experimental methods of non-uniformly correlated beams,and expands the basic applications of coherent beam transmission and imaging on this basis.The results achieved include the following aspects:On the bases of the optical coherence theory,with the help of sufficient conditions for designing bona fide CSD functions,a class of unconventional partially coherent non-uniformly correlated cosine pseudo Shell-mode(CPSM)beams with unconventional circular coherence was designed theoretically,and this type of beam was generated in experiments with high quality.In addition,the mechanism and characteristics of the influence of various optical parameters of the source field on the beam transmission characteristics are also discussed in depth.The research shows that the abnormal self-focusing phenomenon caused by circular coherence will appear during the propagation process,and this phenomenon still exists when the degree of coherence is very low.With the help of cosine function and parameter control,the focal field intensity shaping is realized,and the intensity distributions of Gaussian,flat top and doughnut are obtained.This novel beam shaping method based on coherent structure control has a wide range of applications in laser processing and material processing.By extending the coherent structure control,we propose a partially coherent beam imaging method based on the coherent structure control.The adjustment of the imaging resolution through the coherent structure is the same as that of the coherent light phase control imaging.The important thing is that the imaging of partially coherent beams is very robust and has more practical value than coherent light imaging in practical applications.Twisted phase is a type of two-point cross-correlation phase peculiar to partially coherent light,and its magnitude is determined by the coherence.Twisted partially coherent beams have attracted much attention in recent years because they can carry very high orbital angular momentum.Based on the vector theory,we proposed a self-splitting radially polarized and twisted array beam design method based on the modulation of the correlation structure,and studied the vector transmission characteristics by numerical calculation.It is found the beam self splitting-phenomenon caused by the coherent structure.Due to the existence of twist factor,the light intensity and polarization state will rotate 90 degrees in the focal plane,and the rotation speed is related to the twist factor.The relevant experiments need to be further verified.Twisted beams carry orbital angular momentum,which has a wide range of applications in the light interaction with matter.